Solar cell module having a conductive pattern part

ABSTRACT

A solar cell module is discussed. The solar cell module includes a plurality of solar cells each including a plurality of first current collectors and a plurality of second current collectors, a first protective layer positioned on incident surfaces of the solar cells, a transparent member positioned on the first protective layer, and a conductive pattern part positioned on non-incident surfaces of the plurality of solar cells. The conductive pattern part includes a first pattern having a plurality of first protrusions connected to first current collectors of one solar cell and a second pattern having a plurality of second protrusions connected to second current collectors of the one solar cell. The plurality of first current collectors and the plurality of second current collectors are positioned on a surface of each solar cell on which light is not incident.

This application is a Continuation of U.S. patent application Ser. No.12/938,145, filed on Nov. 2, 2010 now U.S. Pat. No. 8,119,901, whichclaims priority to Korean Patent Application No. 10-2009-0105393, filedon Nov. 3, 2009 and Korean Patent Application No. 10-2010-0097396, filedon Oct. 6, 2010. The entire contents of all of the above applicationsare hereby incorporated by reference.

BACKGROUND OF THE INVENTION

Field of the Invention

Example embodiments of the invention relate to a solar cell module.

Description of the Related Art

Recently, as existing energy sources such as petroleum and coal areexpected to be depleted, interests in alternative energy sources forreplacing the existing energy sources are increasing. Among thealternative energy sources, solar cells generating electric energy fromsolar energy have been particularly spotlighted. Among solar cells, aback contact solar cell, in which both a terminal for outputtingelectrons to the outside and a terminal for outputting holes to theoutside are formed on a back surface of a substrate (i.e., a surface ofthe substrate on which light is not incident), has been developed. Inthe back contact solar cell, a light receiving area is increased, andthus the efficiency of the back contact solar cell is improved.

A panel type solar cell module is manufactured by connecting theplurality of back contact solar cells in series or in parallel to oneanother, so as to obtain a desired output.

SUMMARY OF THE INVENTION

In one aspect, there is a solar cell module including a plurality ofsolar cells, each solar cell including a plurality of first currentcollectors, a plurality of second current collectors, a light incidentsurface and a non-light incident surface, and the plurality of firstcurrent collectors and the plurality of second current collectors beingpositioned on the light incident surface, a first protective layerpositioned on incident surfaces of the plurality of solar cells, atransparent member positioned on the first protective layer, and aconductive pattern part positioned on non-incident surfaces of theplurality of solar cells, the conductive pattern part including a firstpattern having a plurality of first protrusions connected to a pluralityof first current collectors of at least one solar cell and a secondpattern having a plurality of second protrusions connected to aplurality of second current collectors of the at least one solar cell,wherein the plurality of first current collectors of the at least onesolar cell are connected to the plurality of first protrusions and theplurality of second current collectors of the at least one solar cellare connected to the plurality of second protrusions by a conductiveadhesive part that is positioned between the plurality of first currentcollectors of the at least one solar cell and the plurality of firstprotrusions and between the plurality of second current collectors ofthe at least one solar cell and the plurality of second protrusions.

Each of the first pattern and the second pattern may have a thickness ofabout 25 μm to 50 μm.

The plurality of first protrusions and the plurality of secondprotrusions each may have a resistance equal to or less than about0.01179Ω.

A width of each of the plurality of first protrusions may besubstantially equal to a width of each of the plurality of secondprotrusions. The width of each of the plurality of first protrusions maybe different from the width of each of the plurality of secondprotrusions.

A ratio of an area of the second pattern to an area of the first patternmay be 0.6 to 1:1 to 0.6.

The first pattern and the second pattern may be separated from eachother by an insulating material.

The solar cell module may further include a back sheet positioned underthe conductive pattern part.

The solar cell module may further include a second protective layerpositioned between the plurality of solar cells and the conductivepattern part. The second protective layer may have a plurality of firstopenings exposing the plurality of first current collectors and theplurality of second current collectors.

The solar cell module may further include an insulating sheet positionedbetween the second protective layer and the conductive pattern part. Theinsulating sheet may have a plurality of second openings at a locationcorresponding to the plurality of first openings.

A width of each of the plurality of first openings may be substantiallyequal to a width of each of the plurality of second openings. The widthof each of the plurality of first openings may be different from thewidth of each of the plurality of second openings.

The solar cell module may further include a second protective layerpositioned between the conductive pattern part and the back sheet.

The solar cell module may further include an insulating sheet positionedbetween the plurality of solar cells and the conductive pattern part.The insulating sheet may have a plurality of openings exposing theplurality of first current collectors and the plurality of secondcurrent collectors. The insulating sheet may further have a plurality ofholes formed in a portion where the plurality of openings are notpositioned.

The solar cell module may further include an insulating film positionedbetween the conductive pattern part and the second protective layer.

At least one of the insulating film and the conductive pattern part mayhave a plurality of holes.

Each of the plurality of first protrusions and the plurality of secondprotrusions may have a curved edge.

The conductive adhesive part may be formed of a conductive adhesivefilm, a conductive paste, or a conductive epoxy.

The conductive adhesive film may include a resin and conductiveparticles distributed in the resin. The resin may be a thermosettingresin. Each of the conductive particles may have a diameter of about 2μm to 30 μm.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this specification, illustrate embodiments of the invention andtogether with the description serve to explain the principles of theinvention. In the drawings:

FIG. 1 is a perspective view schematically showing a solar cell moduleaccording to an example embodiment of the invention;

FIG. 2 is a partial cross-sectional view of the solar cell module shownin FIG. 1 before a lamination process is performed;

FIG. 3 is a plane view schematically showing an example configuration ofa conductive pattern part of the solar cell module shown in FIG. 1;

FIG. 4 is a partial perspective view of a solar cell according to anexample embodiment of the invention;

FIG. 5 is a cross-sectional view taken along line V-V of FIG. 4;

FIGS. 6 and 7 are plane views schematically showing a back surface ofthe solar cell shown in FIG. 4;

FIG. 8 illustrates another configuration of at least one of a lowerprotective layer and an insulating sheet;

FIG. 9 is a plane view schematically showing another exampleconfiguration of the conductive pattern part of the solar cell moduleshown in FIG. 1;

FIG. 10 is a perspective view schematically showing a solar cell moduleaccording to another example embodiment of the invention;

FIG. 11 is a partial cross-sectional view of the solar cell module shownin FIG. 10 before a lamination process is performed;

FIGS. 12 and 13 are plane views schematically showing variousconfigurations of an insulating sheet of the solar cell module shown inFIG. 10; and

FIGS. 14 and 15 are plane views schematically showing variousconfigurations of a conductive pattern part of the solar cell moduleshown in FIG. 10.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The invention will be described more fully hereinafter with reference tothe accompanying drawings, in which example embodiments of theinventions are shown. This invention may, however, be embodied in manydifferent forms and should not be construed as limited to theembodiments set forth herein.

In the drawings, the thickness of layers, films, panels, regions, etc.,are exaggerated for clarity. Like reference numerals designate likeelements throughout the specification. It will be understood that whenan element such as a layer, film, region, or substrate is referred to asbeing “on” another element, it can be directly on the other element orintervening elements may also be present. In contrast, when an elementis referred to as being “directly on” another element, there are nointervening elements present. Further, it will be understood that whenan element such as a layer, film, region, or substrate is referred to asbeing “entirely” on another element, it may be on the entire surface ofthe other element and may not be on a portion of an edge of the otherelement.

Reference will now be made in detail to embodiments of the invention,examples of which are illustrated in the accompanying drawings.

FIG. 1 is a perspective view schematically showing a solar cell moduleaccording to an example embodiment of the invention.

As shown in FIG. 1, a solar cell module 100 according to an exampleembodiment of the invention includes a plurality of solar cells 1,protective layers 20 a and 20 b for protecting the solar cells 1, atransparent member 40 on the protective layer 20 a (hereinafter,referred to as “upper protective layer”) positioned on light receivingsurfaces of the solar cells 1, an insulating sheet 30 positioned underthe protective layer 20 b (hereinafter, referred to as “lower protectivelayer”) positioned on surfaces, opposite the light receiving surfaces,on which light is not incident, a pattern forming part 50 positionedunder the insulating sheet 30, and a frame 60 for receiving the abovecomponents 1, 20 a, 20 b, 30, 40, and 50.

The transparent member 40 on the light receiving surface of the solarcell module 100 is formed of a tempered glass having a hightransmittance of light to prevent a damage of the solar cell module 100.The tempered glass may be a low iron tempered glass containing a smallamount of iron. The transparent member 40 may have an embossed innersurface so as to increase a scattering effect of light.

The upper and lower protective layers 20 a and 20 b prevent corrosion ofmetal resulting from moisture penetration and protect the solar cellmodule 100 from an impact. The upper and lower protective layers 20 aand 20 b and the plurality of solar cells 1 form an integral body when alamination process is performed in a state where the upper and lowerprotective layers 20 a and 20 b are respectively positioned on and underthe solar cells 1. The upper and lower protective layers 20 a and 20 bmay be formed of ethylene vinyl acetate (EVA), etc. Other materials maybe used.

As shown in FIG. 1, the plurality of solar cells 1 are arranged in amatrix structure. Although FIG. 1 shows the solar cells 1 having thestructure of 3×2 matrix, the number of solar cells 1 in column and/orrow directions may vary, if necessary or desired.

All of the solar cells 1 have the same structure. In the exampleembodiment of the invention, each solar cell 1 is a back contact solarcell in which an electron current collector serving as a terminal foroutputting electrons to the outside and a hole current collector servingas a terminal for outputting holes to the outside are formed on a backsurface of the solar cell 1.

An example configuration of the back contact solar cell is describedbelow with reference to FIGS. 4 and 5.

As shown in FIGS. 4 and 5, the solar cell 1 according to the embodimentof the invention includes a substrate 110 having a plurality of viaholes 181, an emitter layer 120 positioned in the substrate 110, ananti-reflection layer 130 positioned on the emitter layer 120 of anincident surface (hereinafter, referred to as “a front surface”) of thesubstrate 110 on which light is incident, a plurality of frontelectrodes 141 positioned on the emitter layer 120 of the front surfaceof the substrate 110 on which the anti-reflection layer 130 is notpositioned, a plurality of back electrodes 151 positioned on a surface(hereinafter, referred to as “a back surface”), opposite the frontsurface of the substrate 110, on which the light is not incident, aplurality of front electrode current collectors 161, a plurality of backelectrode current collectors 162, and a back surface field (BSF) layer171 positioned on the back surface of the substrate 110. The pluralityof front electrode current collectors 161 (or portions thereof) arepositioned in each of the via holes 181 and on the emitter layer 120 ofthe back surface of the substrate 110 around the via holes 181 and areelectrically connected to the plurality of front electrodes 141. Theback electrode current collectors 162 are positioned on the back surfaceof the substrate 110 and are electrically connected to the backelectrodes 151.

The substrate 110 is a semiconductor substrate, which may be formed offirst conductive type silicon, for example, p-type silicon, though notrequired. Examples of silicon include single crystal silicon,polycrystalline silicon, and amorphous silicon. When the substrate 110is of a p-type, the substrate 110 contains impurities of a group IIIelement such as boron (B), gallium (Ga), and indium (In). Alternatively,the substrate 110 may be of an n-type, and/or be formed of semiconductormaterials other than silicon. If the substrate 110 is of the n-type, thesubstrate 110 may contain impurities of a group V element such asphosphor (P), arsenic (As), and antimony (Sb).

The surface of the substrate 110 is textured to form a textured surfacecorresponding to an uneven surface or having uneven characteristics.FIG. 4 shows that only an edge of the substrate 110 and only an edge ofthe anti-reflection layer 130 on the substrate 110 have a plurality ofuneven portions for the sake of brevity. However, the entire frontsurface of the substrate 110 is the textured surface having theplurality of uneven portions, and thus the anti-reflection layer 130 onthe front surface of the substrate 110 has the textured surface havingthe plurality of uneven portions.

Light incident on the front surface of the substrate 110 are reflectedseveral times because of the anti-reflection layer 130 and the texturedsurface of the substrate 110 having the plurality of uneven portions andis incident to the inside of the substrate 110. Hence, an amount oflight reflected from the front surface of the substrate 110 decreases,and an amount of light incident to the inside of the substrate 110increases. Further, the size of the front surface of the substrate 110and the surface area of the anti-reflection layer 130 increase becauseof the textured surface of the substrate 110. As a result, an amount oflight incident on the substrate 110 increases.

The emitter layer 120 is a region obtained by doping the substrate 110with impurities of a second conductive type (for example, an n-type)opposite the first conductive type of the substrate 110, so as to be ann-type semiconductor, for example. Thus, the emitter layer 120 of thesecond conductive type forms a p-n junction along with the substrate 110of the first conductive type.

A plurality of electron-hole pairs produced by light incident on thesubstrate 110 are separated into electrons and holes by a built-inpotential difference resulting from the p-n junction between thesubstrate 110 and the emitter layer 120. Then, the separated electronsmove to the n-type semiconductor, and the separated holes move to thep-type semiconductor. Thus, when the substrate 110 is of the p-type andthe emitter layer 120 is of the n-type, the separated holes and theseparated electrons move to the substrate 110 and the emitter layer 120,respectively.

Because the emitter layer 120 forms the p-n junction along with thesubstrate 110, the emitter layer 120 may be of the p-type when thesubstrate 110 is of the n-type unlike the embodiment described above. Inthis instance, the separated electrons and the separated holes move tothe substrate 110 and the emitter layer 120, respectively.

Returning to the embodiment of the invention, when the emitter layer 120is of the n-type, the emitter layer 120 may be formed by doping thesubstrate 110 with impurities of a group V element such as P, As, andSb. On the contrary, when the emitter layer 120 is of the p-type, theemitter layer 120 may be formed by doping the substrate 110 withimpurities of a group III element such as B, Ga, and In.

The anti-reflection layer 130 positioned on the emitter layer 120 of thefront surface of the substrate 110 is formed of silicon nitride (SiNx)and/or silicon oxide (SiO_(X)). The anti-reflection layer 130 reduces areflectance of light incident on the solar cell 1 and increasesselectivity of a predetermined wavelength band, thereby increasing theefficiency of the solar cell 1. The anti-reflection layer 130 may have asingle-layered structure or a multi-layered structure such as adouble-layered structure. The anti-reflection layer 130 may be omitted,if desired.

An exposing portion exposing a portion of an edge of the front surfaceof the substrate 110 is formed in the anti-reflection layer 130 and theemitter layer 120 underlying the anti-reflection layer 130. Thus, theexposing portion electrically separates the emitter layer 120 formed inthe front surface of the substrate 110 from the emitter layer 120 formedin the back surface of the substrate 110.

The plurality of front electrodes 141 are positioned on the emitterlayer 120 formed in the front surface of the substrate 110 and areelectrically and physically connected to the emitter layer 120. Thefront electrodes 141 extend substantially parallel to one another in afixed direction.

The front electrodes 141 collect carriers (e.g., electrons) moving tothe emitter layer 120 and transfer the carriers to the front electrodecurrent collectors 161, serving as the electron current collector,electrically connected to the front electrodes 141 through the via holes181. The front electrodes 141 contain at least one conductive material.Examples of the conductive material include at least one selected fromthe group consisting of nickel (Ni), copper (Cu), silver (Ag), aluminum(Al), tin (Sn), zinc (Zn), indium (In), titanium (Ti), gold (Au), and acombination thereof. Other conductive materials may be used.

Each of the plurality of front electrode current collectors 161positioned on the back surface of the substrate 110 is referred to as abus bar and is formed of at least one conductive material. The frontelectrode current collectors 161 extend substantially parallel to oneanother in a direction crossing an extending direction of the frontelectrodes 141 positioned on the front surface of the substrate 110 andthus have a stripe shape.

As shown in FIGS. 4 and 5, the plurality of via holes 181 are formed inthe substrate 110 at crossings of the front electrodes 141 and the frontelectrode current collectors 161. Because at least one of the frontelectrode 141 and the front electrode current collector 161 extends toat least one of the front surface and the back surface of the substrate110 through the via hole 181, the front electrode 141 and the frontelectrode current collector 161 respectively positioned on the oppositesurfaces of the substrate 110 are connected to each other. Hence, thefront electrodes 141 are electrically and physically connected to thefront electrode current collectors 161 through the via holes 181.

The front electrode current collectors 161 output the carrierstransferred from the front electrodes 141 electrically connected to thefront electrode current collectors 161 to an external device.

In the embodiment of the invention, the front electrode currentcollectors 161 contain silver (Ag), but may contain at least oneselected from the group consisting of Ni, Cu, Al, Sn, Zn, In, Ti, Au,and a combination thereof instead of Ag. Other conductive materials maybe used.

The back electrodes 151 on the back surface of the substrate 110 arepositioned to be spaced apart from the front electrode currentcollectors 161 adjacent to the back electrodes 151. The back electrodes151 are positioned on almost the entire back surface of the substrate110 excluding a formation portion of the front electrode currentcollectors 161 at the back surface of the substrate 110. The backelectrodes 151 may not be positioned at an edge of the back surface ofthe substrate 110. The back electrodes 151 collect carriers (e.g.,holes) moving to the substrate 110.

The emitter layer 120 positioned at the back surface of the substrate110 has a plurality of expositing portions 183 that expose a portion ofthe back surface of the substrate 110 and surround the front electrodecurrent collectors 161. The expositing portions 183 block an electricalconnection between the front electrode current collectors 161 collectingelectrons or holes and the back electrodes 151 collecting holes orelectrons, thereby causing the electrons and the holes to move smoothly.

The back electrodes 151 contain at least one conductive material, forexample, aluminum (Al). For example, the back electrodes 151 may containat least one selected from the group consisting of Ni, Cu, Ag, Sn, Zn,In, Ti, Au, and a combination thereof or other conductive materials.

In the embodiment of the invention, the back electrode currentcollectors 162 serving as the hole current collector are positioned onthe back surface of the substrate 110, are electrically and physicallyconnected to the back electrodes 151, and extend parallel to the frontelectrode current collectors 161. Thus, the back electrode currentcollectors 162 collect carriers (for example, holes) transferred fromthe back electrodes 151 and output the carriers to the external device.

The back electrode current collectors 162 are formed of the samematerial as the front electrode current collectors 161. Thus, the backelectrode current collectors 162 contain at least one conductivematerial, for example, silver (Ag). For example, the back electrodecurrent collectors 162 may contain at least one selected from the groupconsisting of Ni, Cu, Al, Sn, Zn, In, Ti, Au, and a combination thereofor other conductive materials.

Although the embodiment of the invention illustrates the two frontelectrode current collectors 161 and the three back electrode currentcollectors 162, the number of front electrode current collectors 161 andthe number of back electrode current collectors 162 may vary if desired.Further, in the embodiment of the invention, the back electrode currentcollectors 162 have a stripe shape long extending in a fixed directionin the same manner as the front electrode current collectors 161.

FIG. 6 illustrates the back surface of the substrate 110 on which thefront electrode current collectors 161 and the back electrode currentcollectors 162 are positioned. As shown in FIG. 6, the front electrodecurrent collectors 161 and the back electrode current collectors 162 arealternately positioned on the back surface of the substrate 110 at aconstant distance therebetween. The back electrodes 151 (or portionsthereof) are positioned between the front electrode current collectors161 and the back electrode current collectors 162. In this instance, theexposing portions 183 are formed along the front electrode currentcollectors 161, so as to provide an electrical insulation between theback electrodes 151 and the front electrode current collectors 161.Hence, a portion of the substrate 110 is exposed through the exposingportions 183.

Unlike the embodiment of the invention discussed above, each backelectrode 151 and each back electrode current collector 162 maypartially overlap each other in other embodiments of the invention. Forexample, a portion of an edge of the back electrode current collector162 may be positioned on the back electrode 151, or a portion of theback electrode 151 may be positioned on the back electrode currentcollector 162. In this instance, a contact area between the backelectrode 151 and the back electrode current collector 162 increases,and a contact resistance between the back electrode 151 and the backelectrode current collector 162 decreases. As a result, a transfer ofcarriers from the back electrode 151 to the back electrode currentcollector 162 may be stably performed because of the stable contacttherebetween.

Alternatively, as shown in FIG. 7, each back electrode current collector162 has an island shape in which a plurality of conductors 1621 arepositioned in a fixed direction at a constant distance therebetween.Each of the plurality of conductors 1621 may have variouscross-sectional shapes such as a rectangle, a triangle, a circle, and anoval. Even in this instance, each conductor 1621 may partially overlapthe back electrode 151.

The back surface field layer 171 is a region (for example, a p⁺-typeregion) obtained by more heavily doping a portion of the back surface ofthe substrate 110 with impurities of the same conductive type as thesubstrate 110 than the substrate 110. Because the back surface fieldlayer 171 is positioned at the back surface of the substrate 110adjoining the back electrodes 151, the back electrodes 151 areelectrically connected to the substrate 110 through the back surfacefield layer 171.

The movement of electrons to the back surface field layer 171 isprevented or reduced and also the movement of holes to the back surfacefield layer 171 is facilitated because of a potential barrier formed bya difference between impurity concentrations of the substrate 110 andthe back surface field layer 171. Thus, a recombination and/or adisappearance of electrons and holes in and around the back surface ofthe substrate 110 are prevented or reduced, and the movement of desiredcarriers (for example, holes) is accelerated. As a result, a transferamount of carriers between the back electrodes 151 and the backelectrode current collectors 162 increases.

The solar cell 1 according to the embodiment of the invention having theabove-described structure is a solar cell in which the front electrodecurrent collectors 161 electrically connected to the front electrodes141 are positioned on the back surface of the substrate 110 on whichlight is not incident. An operation of the solar cell 1 is describedbelow.

When light irradiated to the solar cell 1 is incident on the substrate110 through the emitter layer 120, a plurality of electron-hole pairsare generated in the substrate 110 by light energy based on the incidentlight. Because the surface of the substrate 110 is the textured surface,a light reflectance in the entire surface of the substrate 110 decreasesand an amount of light incident on the substrate 110 increases. Inaddition, because a reflection loss of the light incident on thesubstrate 110 is reduced by the anti-reflection layer 130, an amount oflight incident on the substrate 110 further increases.

The electron-hole pairs are separated into electrons and holes by thep-n junction between the substrate 110 and the emitter layer 120, andthe separated electrons move to the n-type emitter layer 120 and theseparated holes move to the p-type substrate 110. The electrons movingto the n-type emitter layer 120 are collected by the front electrodes141 and then move to the front electrode current collectors 161electrically connected to the front electrodes 141 through the via holes181. The holes moving to the p-type substrate 110 are collected by theback electrodes 151 through the back surface field layer 171 and thenmove to the back electrode current collectors 162. When the frontelectrode current collectors 161 are connected to the back electrodecurrent collectors 162 using electric wires, current flows therein tothereby enable use of the current for electric power.

Returning again to FIGS. 1 to 3, the lower protective layer 20 bunderlying the plurality of solar cells 1 has a plurality of openings21, unlike the upper protective layer 20 a. Thus, the upper protectivelayer 20 a and the lower protective layer 20 b have differentstructures.

A location of the openings 21 corresponds to the current collectors 161and 162 of each solar cell 1, and at least a portion of thecorresponding current collector is exposed through each opening 21. Inthis instance, a width of the opening 21 is equal to or less than widthsof the current collectors 161 and 162. However, the width of the opening21 may be greater than the widths of the current collectors 161 and 162.

The insulating sheet 30 between the lower protective layer 20 b and thepattern forming part 50 is formed of an insulating material andinsulates between the lower protective layer 20 b and the patternforming part 50. The insulating sheet 30 has a plurality of openings 31.A location of the openings 31 corresponds to the openings 21 of thelower protective layer 20 b, and at least a portion of the correspondingcurrent collector is exposed through each opening 31.

As shown in FIG. 2, a width D2 of the opening 31 of the insulating sheet30 is substantially equal to a width D1 of the opening 21 of the lowerprotective layer 20 b. However, the width D2 and the width D1 may bedifferent from each other. For example, the width D2 of the opening 31of the insulating sheet 30 may be less or greater than the width D1 ofthe opening 21 of the lower protective layer 20 b.

As shown in FIG. 1, the openings 21 and 31 have lengths and widthscorresponding to lengths and widths of the current collectors 161 and162 opposite the openings 21 and 31 and have a stripe shape longextending in a fixed direction.

However, unlike the shape shown in FIG. 1, as shown in FIG. 8, at leastone of the openings 21 and 31 may have the structure in which aplurality of holes 211 are arranged along the extending direction of thecurrent collectors 161 and 162. Each hole 211 may have variouscross-sectional shapes such as a circle, a polygon and an oval, and adistance between the holes 211 may be uniform or non-uniform. Further,the size and the number of holes 211 may be determined based on thelength and the width of the current collectors 161 and 162. In thisinstance, the current collectors 161 and 162 are exposed through theholes 211.

The pattern forming part 50 electrically connects the plurality of solarcells 1 to one another and prevents the moisture from penetrating into aback surface of the solar cell module 100, thereby protecting theplurality of solar cells 1 from an external environment. As shown inFIGS. 1 and 2, the pattern forming part 50 includes a back sheet 52 anda conductive pattern part 51 on the back sheet 52.

The back sheet 52 is formed using a thin sheet formed of an insulatingmaterial such as fluoropolymer/polyester/fluoropolymer (FP/PE/FP). Otherinsulating materials may be used. The back sheet 52 prevents moistureand oxygen from penetrating into the back surface of the solar cellmodule 100, thereby protecting the solar cells 1 from the externalenvironment. The back sheet 52 may have a multi-layered structureincluding a moisture/oxygen penetrating prevention layer, a chemicalcorrosion prevention layer, an insulation layer, etc.

The conductive pattern part 51 is positioned on the back sheet 51. Inthe embodiment of the invention, the conductive pattern part 51 isformed of copper (Cu). However, the conductive pattern part 51 may beformed of different conductive materials, for example, silver (Ag),aluminum (Al), or nickel (Ni).

Another conductive layer may be formed on the conductive pattern part 51by coating a conductive material on the conductive pattern part 51, soas to improve the conductivity of the conductive pattern part 51 andcontact characteristic between the conductive pattern part 51 and thesolar cells 1. The conductive pattern part 51 and the conductive layermay be formed of the same conductive material or different conductivematerials each having different characteristic. When the conductivepattern part 51 and the conductive layer are formed of the differentconductive materials, the conductivity of the conductive layer may bemore excellent (or improved) than the conductivity of the conductivepattern part 51 alone. In this instance, the conductive pattern part 51may be formed of Al or Ni, etc., and the conductive layer on theconductive pattern part 51 may be formed of Au or Ag, etc.

In the embodiment shown in FIG. 3, the pattern forming part 50 and theconductive pattern part 51 are able to accommodate six solar cells 1,although such is not required, whereby three solar cells 1 may bedisposed in the upper row, and three solar cells 1 may be disposed inthe lower row. Starting at the upper left corner of the pattern formingpart 50 and counting in a clockwise direction, it can be seen that firstthrough sixth solar cells 1 may be accommodated by the pattern formingpart 50.

The conductive pattern part 51 has a plurality of front electrodepatterns 511 contacting the plurality of front electrode currentcollectors 161 of each solar cell 1, a plurality of back electrodepatterns 512 contacting the plurality of back electrode currentcollectors 162 of each solar cell 1, and a separation part 513 forseparating the front electrode patterns 511 and the back electrodepatterns 512. Thus, the insulating material of the back sheet 52 isexposed in a formation portion of the separation part 513. When thelamination process is performed, the separation part 513 is filled withthe insulating material of the back sheet 52. A width of the separationpart 513 may be adjusted based on the number and the size of each of thefront electrode patterns 511 and the back electrode patterns 512, thesize of the back sheet 52 on which the conductive pattern part 51 ispositioned, a distance between the adjacent solar cells 1 arranged inthe matrix structure, etc.

The front electrode patterns 511 and the back electrode patterns 512respectively include main branches 511 a and 512 a extending in atransverse direction and sub-branches (i.e., protrusions) 511 b and 512b that extend from the main branches 511 a and 512 a in a longitudinaldirection and have a comb teeth shape. The protrusions 511 b and 512 bare separated from each other by the size (i.e., a width) of theseparation part 513 and are dovetailed into each other. Thus, a pair ofelectrode patterns 511 and 512 corresponding to one solar cell 1 areelectrically insulated from each other by the separation part 513.

Further, in the electrode patterns 511 and 512 corresponding to the twosolar cells 1 that are positioned adjacent to each other in a rowdirection on the same row (for example, second and third solar cellsaccording to the convention defined above), the front electrode pattern511 corresponding to one current collector (for example, the frontelectrode current collector 161) of one solar cell 1 (the second solarcell) of the two solar cells 1 is connected to the back electrodepattern 512 corresponding to one current collector (for example, theback electrode current collector 162) of the other solar cell 1 (thethird solar cell) of the two solar cells 1. In this instance, the backelectrode pattern 512 of the one solar cell 1 (the second solar cell)and the front electrode pattern 511 of the other solar cell 1 (the thirdsolar cell), which are not connected to each other, are connected to theelectrode patterns 511 and 512 corresponding to other solar cells 1(respectively the first solar cell and the fourth solar cell) adjacentto the two solar cells 1 (the second and third solar cells) in the rowdirection.

In addition, in the electrode patterns 511 and 512 corresponding to thetwo solar cells 1 that are positioned on different lines and areadjacent to each other in a first column (the first and sixth solarcells) or a last column in a column direction (the third and fourthsolar cells), the front electrode pattern 511 corresponding to onecurrent collector (for example, the front electrode current collector161) of one solar cell 1 (third solar cell) of the two solar cells 1 isconnected to the back electrode pattern 512 corresponding to one currentcollector (for example, the back electrode current collector 162) of theother solar cell 1 (the fourth solar cell) of the two solar cells 1. Inthis instance, the back electrode pattern 512 of the one solar cell 1(the third solar cell) and the front electrode pattern 511 of the othersolar cell 1 (the fourth solar cell), that are not connected to eachother, are connected to the electrode patterns 511 and 512 correspondingto other solar cells 1 (respectively the second solar cell and the fifthsolar cell) adjacent to the two solar cells 1 (the third and fourthsolar cells) in the line direction.

In the conductive pattern part 51, the different kinds of electrodepatterns 511 and 512 not connected to the different kinds of electrodepatterns 512 and 511 are connected to an external device (for example, ajunction box) positioned on a back surface (i.e., a lower portion) ofthe pattern forming part 50 through a separate wire or a conductivetape.

Hence, the front electrode current collectors 161 of each solar cell 1exposed through the openings 31 of the insulating sheet 30 and theopenings 21 of the lower protective layer 20 b are positioned oppositethe front electrode patterns 511 of the conductive pattern part 51.Further, the back electrode current collectors 162 of each solar cell 1exposed through the openings 21 and 31 are positioned opposite the backelectrode patterns 512 of the conductive pattern part 51.

As shown in FIG. 3, widths w1 of the protrusions 511 b of the frontelectrode patterns 511 are substantially equal to one another, andwidths w2 of the protrusions 512 b of the back electrode patterns 512are substantially equal to one another. Further, the width w1 of theprotrusion 511 b of the front electrode pattern 511 is greater than thewidth w2 of the protrusion 512 b of the back electrode pattern 512, butis not limited thereto.

More specifically, the width w1 of the protrusion 511 b of the frontelectrode pattern 511 may be equal to or greater than the width w2 ofthe protrusion 512 b of the back electrode pattern 512. The widths w1and w2 of the protrusions 511 b and 512 b may be determined based on thenumber of front electrode current collectors 161 and the number of backelectrode current collectors 162. For example, as the number of currentcollectors 161 and 162 increases, an amount of current flowing throughthe protrusions 511 b and 512 b decreases. Thus, as an amount of currentflowing through the protrusions 511 b and 512 b (i.e., an amount ofload) decreases, the widths w1 and w2 of the protrusions 511 b and 512 bdecrease. In the embodiment of the invention, because the two frontelectrode current collectors 161 and the three back electrode currentcollectors 162 are positioned (or exists) on the back surface of thesubstrate 110, the width w1 of the front electrode pattern 511 isgreater than the width w2 of the back electrode pattern 512. Further, aratio of an area of the back electrode pattern 512 to an area of thefront electrode pattern 511 is approximately 0.6 to 1:1 to 0.6. That is,the ratio of the area of the back electrode pattern 512 to the area ofthe front electrode pattern 511 is X:Y, when the area of area of theback electrode pattern 512 is represented by X and the area of the frontelectrode pattern 511 is represented by Y, where X may vary fromapproximately 0.6 to 1 and Y may vary from approximately 1 to 0.6. Whenthe above area ratio between the electrode patterns 511 and 512 issatisfied, carriers transferred to the electrode patterns 511 and 512may be more smoothly transferred, and the size of each of the electrodepatterns 511 and 512 may be properly determined suitable for the size(for example, a width of a long axis) of the conductive pattern part 51.

A thickness of each of the electrode patterns 511 and 512 may beapproximately 25 μm to 50 μm. When the thickness of each of theelectrode patterns 511 and 512 is equal to or greater than approximately25 μm, the conductivity having a desired intensity is obtained. When thethickness of each of the electrode patterns 511 and 512 is equal to orless than approximately 50 μm, the electrode patterns 511 and 512 maysmoothly contact the corresponding portions of the solar cell 1 whilereducing a difficulty in forming the electrode patterns 511 and 512through an etching process, etc. Further, when the separation part 513is filled with the formation material (i.e., the insulating material) ofthe back sheet 52 during the lamination process, the separation part 513may be stably filled with the insulating material because the separationpart 513 is not very deep (i.e., a thickness of the separation part 513is not very large). Hence, the electrical insulation between the frontelectrode pattern 511 and the back electrode pattern 512 may be stablyprovided.

Resistances of the protrusions 511 b and 512 b contacting the currentcollectors 161 and 162 exposed through the openings 21 and 31 are mainlyaffected by a cross-sectional area (=width×height) and a length of eachof the protrusions 511 b and 512 b of the electrode patterns 511 and512. As the cross-sectional areas of the protrusions 511 b and 512 bincrease, the resistances of the protrusions 511 b and 512 b decrease.Further, as the lengths of the protrusions 511 b and 512 b increase, theresistances of the protrusions 511 b and 512 b increases.

Accordingly, the resistance of each of the protrusions 511 b and 512 bhas to be maintained to be equal to less than a setting value (or apredetermined value), so as to smoothly perform a transfer of carriesusing the protrusions 511 b and 512 b. In other words, when theresistance of each of the protrusions 511 b and 512 b is greater thanthe setting value, the transfer of carries is not smoothly performedbecause of the resistances of the protrusions 511 b and 512 b. In theembodiment of the invention, the setting value, i.e., a maximumresistance is approximately 0.01179Ω. Each of the protrusions 511 b and512 b has to have the cross-sectional area equal to or greater than22.5×10⁻⁸ m², so that each of the protrusions 511 b and 512 b has aresistance equal to or less than the maximum resistance. The maximumresistance is set based on a resistance of a separate conductive tape,such as a ribbon, that is attached on the front electrode currentcollectors 161 and the back electrode current collectors 162 of eachsolar cell 1 and electrically connects the solar cells 1 to one another.When the resistance of each of the protrusions 511 b and 512 b ismaintained to be equal to or less than the resistance of the ribbonattached to each solar cell 1, a current normally flows in the solarcells 1.

The lengths of the protrusions 511 b and 512 b are substantially equalto one another and are determined based on the length of the solar cell1. Thus, each of the protrusions 511 b and 512 b may have a desiredcross-sectional area by properly adjusting the thicknesses and thewidths w1 and w2 of the protrusions 511 b and 512 b. The length of thesolar cell 1 is a length of the solar cell 1 measured along theextending direction of the current collectors 161 and 162.

For this, the widths w1 and w2 of the protrusions 511 b and 512 b isapproximately 2.1 mm to 8.6 mm. When the conductive pattern part 51 isformed of copper (Cu), a specific resistance of each of the protrusions511 b and 512 b has a uniform value of approximately 1.72×10⁻⁸ Ω/m.

For example, when the pattern part 51 is formed of copper (Cu) and thelength of the solar cell 1 measured along the extending direction of thecurrent collectors 161 and 162 is approximately 156 mm, the thickness ofeach of the protrusions 511 b and 512 b may be approximately 35 μm whenat least one of the widths w1 and w2 of the protrusions 511 b and 512 bis approximately 6.4 mm.

As above, each of the protrusions 511 b and 512 b may have a desiredcross-sectional area equal to or greater than a reference value byproperly adjusting the thicknesses and the widths w1 and w2 of theprotrusions 511 b and 512 b. Hence, a stable output of carriers isperformed.

As shown in FIG. 2, a conductive adhesive part 54 is positioned on theopening 31 of the insulating sheet 30. The conductive adhesive part 54is filled in the openings 21 and 31 because of heat generated when thelamination process is performed. Hence, the current collectors 161 and162 exposed through the openings 21 and 31 contact the conductivepattern part 51 by the conductive adhesive part 54 positioned in theopenings 21 and 31.

The conductive adhesive part 54 may be formed of a conductive adhesivefilm, a conductive paste, a conductive epoxy, etc.

The conductive adhesive film may include a resin and conductiveparticles distributed in the resin. A material of the resin is notparticularly limited as long as it has the adhesive property. It ispreferable, but not required, that a thermosetting resin is used for theresin so as to increase the adhesive reliability. The thermosettingresin may use at least one selected among epoxy resin, phenoxy resin,acryl resin, polyimide resin, and polycarbonate resin.

The resin may further contain a predetermined material, for example, aknown curing agent and a known curing accelerator other than thethermosetting resin. For example, the resin may contain a reformingmaterial such as a silane-based coupling agent, a titanate-basedcoupling agent, and an aluminate-based coupling agent, so as to improvean adhesive strength between the conductive pattern part 51 and thesolar cells 1. The resin may contain a dispersing agent such as calciumphosphate and calcium carbonate, so as to improve the dispersibility ofthe conductive particles. The resin may contain a rubber component suchas acrylic rubber, silicon rubber, and urethane rubber, so as to controlthe modulus of elasticity of the conductive adhesive film.

A material of the conductive particles is not particularly limited aslong as it has the conductivity. The conductive particles may contain atleast one metal selected among copper (Cu), silver (Ag), gold (Au), iron(Fe), nickel (Ni), lead (Pb), zinc (Zn), cobalt (Co), titanium (Ti), andmagnesium (Mg) as the main component. The conductive particles may beformed of only metal particles or metal-coated resin particles. Theconductive adhesive film having the above-described configuration mayinclude a peeling film.

It is preferable, but not required, that the conductive particles usethe metal-coated resin particles, so as to mitigate a compressive stressof the conductive particles and improve the connection reliability ofthe conductive particles. It is preferable, but not required, that theconductive particles have a diameter of 2 μm to 30 μm, so as to improvethe dispersibility of the conductive particles.

It is preferable, but not required, that a composition amount of theconductive particles distributed in the resin is 0.5% to 20% based onthe total volume of the conductive adhesive film in consideration of theconnection reliability after the resin is cured. When the compositionamount of the conductive particles is less than 0.5%, a current may notsmoothly flow because a physical contact area between the conductiveadhesive part 54 and the front electrodes 141 decreases. When thecomposition amount of the conductive particles is greater than 20%, theadhesive strength may be reduced because a composition amount of theresin relatively decreases.

As a result, the protrusion 511 b of each front electrode pattern 511 ofthe conductive pattern part 51 positioned on the back sheet 52 iselectrically connected to the front electrode current collectors 161 ofthe solar cell 1 corresponding to the conductive pattern part 51.Further, the protrusion 512 b of each back electrode pattern 512 of theconductive pattern part 51 is electrically connected to the backelectrode current collectors 162 of the solar cell 1 corresponding tothe conductive pattern part 51.

As described above, the protrusions 511 b of the front electrodepatterns 511 corresponding to each solar cell 1 are connected to oneanother by the main branch 511 a, and the protrusions 512 b of the backelectrode patterns 512 corresponding to each solar cell 1 are connectedto one another by the main branch 512 a. Therefore, the front electrodecurrent collectors 161 of each solar cell 1 are connected to one anotherby the front electrode patterns 511, and the back electrode currentcollectors 162 of each solar cell 1 are connected to one another by theback electrode patterns 512.

Further, as described above, the plurality of solar cells 1 areconnected in series to one another by the connection structure betweenthe electrode patterns 511 and 512 of the conductive pattern part 51 anda formation location of the separation part 513. Because the differentpatterns 511 and 512 of the conductive pattern part 51 are connected tothe external device, carriers output by the plurality of solar cells 1connected in series are output to the external device, thereby allowinga current to flow.

In the embodiment of the invention, instead of the electrical connectionof the solar cells 1 using the separate ribbon, the electricalconnection of the solar cells 1 is automatically performed by thepattern forming part 50 having the separate conductive pattern part 51.

In other words, the insulating sheet 30 is positioned on the patternforming part 50, and the conductive adhesive part 54 is positioned at alocation corresponding to a formation location of the insulating sheet30. Then, the lower protective layer 20 b is positioned on theinsulating sheet 30.

Next, the plurality of solar cells 1 are positioned at a uniformdistance therebetween, the upper protective layer 20 a is arranged onthe solar cells 1, and the transparent member 40 is positioned on theupper protective layer 20 a.

Next, the lamination process is performed to form an integral body ofthe components 1, 20 a, 20 b, 30, 40, and 50. More specifically, theupper and lower protective layers 20 a and 20 b are melted because ofheat generated when the lamination process is performed. The meltedupper and lower protective layers 20 a and 20 b are filled in a spacebetween the components. The transparent member 40, the upper protectivelayer 20 a, the solar cells 1, the lower protective layer 20 b, theinsulating sheet 30, and the pattern forming part 50 are attached to oneanother to form the integral body. Thus, the protective layers 20 a and20 b form one protective member through the lamination process. Thematerial (for example, ethylene vinyl acetate (EVA)) forming the oneprotective member surrounds the solar cells 1 and protects the solarcells 1 from impact or moisture.

Further, the conductive adhesive part 54 is filled in the openings 21and 31 because of the heat generated when the lamination process isperformed. The front electrode current collectors 161 and the backelectrode current collectors 162 of each solar cell 1 are connected tothe conductive pattern part 51 of the pattern forming part 50 by theconductive adhesive part 54.

Thus, instead of a process in which the ribbon is cut and then isattached on the current collectors 161 and 162 of the solar cells 1, theelectrical connection of the solar cells 1 is automatically completedthrough the lamination process performed using the conductive patternpart 51 having a desired pattern. As a result, manufacturing time of thesolar cell module 100 is reduced, and thus the production efficiency ofthe solar cell module 100 is improved.

FIGS. 1 and 2 illustrates that the conductive pattern part 51 and theback sheet 52 are manufactured to form an integral body, i.e., thepattern forming part 50. In this instance, the conductive pattern part51 is formed by forming a conductive layer formed of copper (Cu), etc.on the back sheet 52, patterning the conductive layer in a desired shapeusing a dry etching method or a wet etching method, etc., and formingthe conductive layer having the desired shape on the back sheet 52.

However, the conductive pattern part 51 and the back sheet 52 may bemanufactured as a separate part. In this instance, the conductivepattern part 51, which is patterned in a desired shape to have a sheetform, is positioned on the back sheet 52 as a separate part. A formationlocation of the conductive pattern part 51 is determined inconsideration of formation locations of the openings 21 of the lowerprotective layer 20 b and the openings 31 of the insulating sheet 30.Hence, when the conductive pattern part 51 and the back sheet 52 aremanufactured as a separate part, only the back sheet 52 serves as a backsheet.

Further, the insulating sheet 30 and the pattern forming part 50 may bemanufactured to form an integral body. In this instance, the patternforming part 50 may include the insulating sheet 30, the conductivepattern part 51, and the back sheet 52.

FIG. 2 shows the conductive adhesive part 54 positioned on theinsulating sheet 30. However, the conductive adhesive part 54 may bepositioned on the lower protective layer 20 b or on the insulating sheet30 and the conductive pattern part 51. When the conductive adhesive part54 is positioned on the lower protective layer 20 b, the conductiveadhesive part 54 may be positioned on the openings 21 of the lowerprotective layer 20 b. When the conductive adhesive part 54 ispositioned on the conductive pattern part 51, the conductive adhesivepart 54 may be positioned at a location corresponding to the openings 31of the insulating sheet 30.

The frame 60 receives the components 50, 31, 20 b, 1, 20 a, and 40forming an integral body. The frame 60 is formed of a material, forexample, aluminum coated with an insulating material that does notgenerate corrosion, deformation, etc., under influence of the externalenvironment. The frame 60 has the structure in which the drainageprocess, the installation, and the execution are easily performed.

As shown in FIG. 3, each of the protrusions 511 b and 512 b has anangular edge. However, as shown in FIG. 9, the edge of each of theprotrusions 511 b and 512 b may have a curved shape. When the edge ofeach of the protrusions 511 b and 512 b has the angular shape, carriersmay concentrate in an angular portion (i.e., the angular edge) of eachof the protrusions 511 b and 512 b. Hence, the carriers are notuniformly distributed in each of the protrusions 511 b and 512 b, andthe problem such as an arc is caused. However, when the edge of each ofthe protrusions 511 b and 512 b has the curved shape as shown in FIG. 9,the carriers are uniformly distributed in each of the protrusions 511 band 512 b. Hence, the electrical problem such as the arc is prevented orreduced.

A solar cell module according to another example embodiment of theinvention is described in detail below with reference to FIGS. 10 and11.

FIG. 10 is a perspective view schematically showing a solar cell moduleaccording to another example embodiment of the invention. FIG. 11 is apartial cross-sectional view of the solar cell module shown in FIG. 10before a lamination process is performed.

Structures and components identical or equivalent to those illustratedin FIGS. 1 and 2 are designated with the same reference numerals, and afurther description may be briefly made or may be entirely omitted.

Unlike the solar cell module 100 shown in FIGS. 1 and 2 in which thepattern forming part 50 is positioned under the lower protective layer20 b, a pattern forming part 50 of a solar cell module 100 a sown inFIG. 10 is positioned on a lower protective layer 20 b 1. Thus, aformation order and a shape of the lower protective layer 20 b 1 of thesolar cell module 100 a are different from the solar cell module 100.

The solar cell module 100 a is described in detail below.

As shown in FIGS. 10 and 11, the solar cell module 100 a includes aplurality of solar cells 1 arranged in a matrix structure, a upperprotective layer 20 a positioned on the solar cells 1, an insulatingsheet 30 positioned under the solar cells 1, a pattern forming part 50 apositioned under the insulating sheet 30, a lower protective layer 20 b1 positioned under the pattern forming part 50 a, and a back sheet 53positioned under the lower protective layer 20 b 1.

As described above, the insulating sheet 30 shown in FIGS. 10 and 11 hassubstantially the same operation and structure as the insulating sheet30 shown in FIGS. 1 and 2, except that the insulating sheet 30 shown inFIGS. 10 and 11 is positioned directly under the solar cells 1.

As described above, the pattern forming part 50 a electrically connectsthe plurality of solar cells 1 to one another and includes an insulatingfilm 52 a formed of an insulating material and a conductive pattern part51 positioned on the insulating film 52 a.

Thus, as shown in FIG. 11, because a conductive adhesive part 54 ispositioned on the openings 31 of the insulating sheet 30, as describedabove with reference to FIGS. 1 to 9, the front electrode currentcollectors 161 and the back electrode current collectors 162 of thesolar cell 1 are connected to the front electrode patterns 511 and theback electrode patterns 512 of the conductive pattern part 51 throughthe conductive adhesive part 54. Hence, the electrical connectionbetween the plurality of solar cells 1 is performed.

Configuration of the conductive pattern part 51 of the pattern formingpart 50 a is substantially the same as the conductive pattern part 51 ofthe pattern forming part 50 shown in FIGS. 1 and 2.

Because the lower protective layer 20 b 1 is positioned under thepattern forming part 50 a used to electrically connect the solar cells 1to one another, the lower protective layer 20 b 1 does not include aplurality of openings unlike the lower protective layer 20 b shown inFIGS. 1 and 2. Thus, the shapes of the upper protective layer 20 a andthe lower protective layer 20 b 1 shown in FIGS. 10 and 11 aresubstantially the same as each other. The lower protective layer 20 b 1shown in FIGS. 10 and 11 is formed of the same material as the lowerprotective layer 20 b shown in FIGS. 1 and 2 and performs the sameoperation as the lower protective layer 20 b except the above structuraldifference.

The back sheet 53 prevents the moisture from penetrating into a backsurface of the solar cell module 100 a, thereby protecting the pluralityof solar cells 1 from an external environment, in the same manner as theback sheet 52 shown in FIGS. 1 and 2. The back sheet 53 is formed of aninsulating material such as fluoropolymer/polyester/fluoropolymer(FP/PE/FP).

However, as shown in (a) of FIG. 12 and (b) of FIG. 12, the insulatingsheet 30 has a plurality of holes 32 as well as a plurality of openings31 exposing the front electrode current collectors 161 and the backelectrode current collectors 162. Namely, the insulating sheet 30 has aporous pattern.

A cross-sectional shape of each hole 32 shown in (a) of FIG. 12 is acircle, but may also have various shapes such as a polygon or an oval,for example. Further, the holes 32 may be formed at a uniform distancetherebetween or at a non-uniform distance therebetween. Diameters of theholes 32 may be substantially equal to one another. Alternatively, atleast two of the diameters of the holes 32 may be different from theother diameters.

As shown in (b) of FIG. 12, when the cross-sectional shape of each hole32 is a rectangle, the insulating sheet 30 may have a net-shapedpattern.

As shown in (a) of FIG. 12 and (b) of FIG. 12, the plurality of openings31 exposing the front electrode current collectors 161 and the backelectrode current collectors 162 have a stripe shape. However, asdescribed above with reference to FIG. 8, the cross-sectional shape ofeach opening 31 may be a circle, a polygon, or an oval, for example. Theopenings 31 may have the structure in which a plurality of holes 211 arearranged along the current collectors 161 and 162. In this instance, theinsulating sheet 30 may have a pattern shown in FIGS. 13(a) and 13(b).

The insulating film 52 a may have a porous pattern in the same manner asthe insulating sheet 30. In this instance, because the insulating film52 a does not have a plurality of openings (for example, openings 21 or31) exposing the front electrode current collectors 161 and the backelectrode current collectors 162, a plurality of holes 32 are formed onthe entire surface of the insulating film 52 a in a fixed pattern. Anexample where the insulating film 52 a has the porous pattern may besubstantially the same as the pattern illustrated in (a) of FIG. 13 and(b) of FIG. 13.

Further, the conductive pattern part 51 may have a porous pattern havinga plurality of holes 32. An example where the conductive pattern part 51has the porous pattern is illustrated in FIGS. 14 and 15. As describedabove, the shape of the holes 32 may be an oval, a polygon, or a circle.Distances between the holes 32 may be substantially equal to ordifferent from one another, and diameters of the holes 32 may besubstantially equal to or different from one another.

As above, when at least one of the insulating sheet 30, the insulatingfilm 52 a, and the conductive pattern part 51 has the porous patternhaving the plurality of holes 32, the upper and lower protective layers20 a and 20 b 1 may be melted because of heat generated when thelamination process is performed to form one protective member, and theone protective member thus formed may surround the plurality of solarcells 1. In this instance, because the formation material of the lowerprotective layer 20 b 1 smoothly moves to the plurality of solar cells 1through the plurality of holes 32, the upper and lower protective layers20 a and 20 b 1 may stably and easily perform a sealing operation.

The insulating film 52 a and the conductive pattern part 51 of thepattern forming part 50 a may be manufactured to form an integral bodyin the same manner as the pattern forming part 50, or may bemanufactured as a separated part.

Further, FIG. 11 shows the conductive adhesive part 54 positioned on theinsulating sheet 30, whereby the conductive adhesive part 54 may be thenpositioned on the insulating sheet 30 and the conductive pattern part51. When the conductive adhesive part 54 is positioned on the conductivepattern part 51, the conductive adhesive part 54 may be positioned at alocation corresponding to the openings 31 of the insulating sheet 30.

As described above, in the solar cell module 100 a according to theembodiment of the invention, the electrical connection between theplurality of solar cells 1 is easily and rapidly performed because ofthe pattern forming part 50 a having the conductive pattern part 51.

Although embodiments have been described with reference to a number ofillustrative embodiments thereof, it should be understood that numerousother modifications and embodiments can be devised by those skilled inthe art that will fall within the scope of the principles of thisdisclosure. More particularly, various variations and modifications arepossible in the component parts and/or arrangements of the subjectcombination arrangement within the scope of the disclosure, the drawingsand the appended claims. In addition to variations and modifications inthe component parts and/or arrangements, alternative uses will also beapparent to those skilled in the art.

What is claimed is:
 1. A solar cell module, comprising: a back sheetmade of an insulating material; a conductive pattern part positionedover the back sheet, the conductive pattern part including a firstpattern and a second pattern; a plurality of solar cells positioned overthe conductive pattern part, each solar cell including a firstelectrode, and a second electrode, the first and second electrodes beingpositioned on a back surface, which is opposite to a light incidentsurface of the each solar cell; an insulating member positioned betweenthe plurality of solar cells and the conductive pattern part, theinsulating member comprising a plurality of openings exposing the firstelectrode and the second electrode, respectively; a front substratepositioned on a front surface of the plurality of solar cells; an upperprotective layer between the front substrate and the plurality of solarcells; and a lower protective layer between the back sheet and theplurality of solar cells, wherein each of the first and second patternshas a plurality of protrusions being opposite to each other, theprotrusions of the first pattern are connected to the first electrode ofeach solar cell, the protrusions of the second pattern are connected tothe second electrode of each solar cell, and the protrusions of thefirst pattern are spaced apart from the protrusions of the secondpattern in an overlapping area of each solar cell, the protrusions ofthe first pattern are connected to the first electrode through theplurality of openings of the insulating member, the protrusions of thesecond pattern are connected to the second electrode through theplurality of openings of the insulating member, and the first and secondpatterns are connected to each other in an area between two adjacentsolar cells so that the first electrode of one solar cell of twoadjacent solar cells is connected to the second electrode of anothersolar cell of the two adjacent solar cells, the plurality of openingsare filled with a conductive adhesive to electrically connect the firstelectrode to the first pattern and the second electrode to the secondpattern, each of the first electrode and the second electrode includes aplurality of elongated portions extended in a first lengthwisedirection, and the plurality of elongated portions of the firstelectrode extended in the first lengthwise direction and the pluralityof elongated portions of the second electrode extended in the firstlengthwise direction are alternatively arranged, and the plurality ofopenings of the insulating member are elongated in the first lengthwisedirection and expose the plurality of portions of first electrode andthe plurality of elongated portions of the second electrode extended inthe first lengthwise direction.
 2. The solar cell module of claim 1,wherein the lower protective layer is positioned between the insulatingmember and the plurality of solar cells.
 3. The solar cell module ofclaim 1, wherein the lower protective layer comprises a plurality ofsecond openings at positions the same as positions of the plurality ofopenings of the insulating member.
 4. The solar cell module of claim 3,wherein a width of the plurality of openings of the insulating member isdifferent from a width of each second opening of the lower protectivelayer.
 5. The solar cell module of claim 1, wherein the upper protectivelayer and the lower protective layer are made of ethylene vinyl acetate(EVA).
 6. The solar cell module of claim 1, wherein the conductivepattern part comprises a plurality of holes.
 7. The solar cell module ofclaim 1, wherein the first pattern and the second pattern of theconductive pattern part are formed separated on the back sheet.
 8. Thesolar cell module of claim 1, wherein the conductive adhesive comprisesa resin and conductive particles distributed in the resin.
 9. The solarcell module of claim 1, wherein a number of the first electrode is lessthan a number of the second electrode.
 10. The solar cell module ofclaim 1, wherein the conductive pattern part is formed on an insulatingfilm positioned on the back sheet.
 11. The solar cell module of claim10, wherein the lower protective layer is positioned between the backsheet and the insulating film.
 12. The solar cell module claim 1,wherein an edge of each of the plurality of protrusions has a curvedshape.
 13. The solar cell module claim 1, wherein a width of the firstpattern is different from a width of the second pattern.
 14. The solarcell module claim 1, wherein an area of the first pattern is differentfrom an area of the second pattern.
 15. The solar cell module claim 1,wherein each of the first pattern and the second pattern has a thicknessof 25 μm to 50 μm.